IIG TRANSACTIONS AND PROCEEDINGS OF THE [Sess. LXii. 



are left without any clue as to which of them it was. In 

 order to determine that point, a set of experiments would 

 be required, with soils artiticially prepared, in which each 

 of these constituents in turn was made to predominate, or 

 in wiiich each of them in turn was deficient. It would be 

 easy to prepare soils of that kind and to grow bulbs in 

 them, but it would, perhaps, be a long time before any 

 definite results could be obtained, for the colour differences 

 observed are probably the result of a long course of breeding- 

 through many generations of plants, and the rate of change 

 would be slower in the case of bull)S than in that of most 

 plants, for bulbs contain within them a large store of the 

 nutrition required for the production of flowers, and they 

 are not so dependent as most other plants upon the 

 immediate supply of food they are able to abstract from 

 the soil. 



It is probable that an analysis of the bulbs themselves 

 would lead more rapidly to the solution of the problem, 

 for it is not so much the quantities of the various food 

 constituents contained in the soil, as the amounts of these 

 that the plants are able to assimilate, which determines the 

 effects the}' are able to produce. It is evident, therefore, 

 that the analyses here given form only the beginning of 

 what, if not a very important, is at least a very interesting 

 inquiry. 



Notes on Hybrid Violas. (With Specimens.) l')y 

 James Grieve, Redbraes Nursery. 



(Koarl litli May IS'JS.) 



Mr. (Jrieve gave a few notes on various hybrid violas 

 produced by him during thirty years of careful cross- 

 breeding, using as seed-bearing parents Viola hitca, 

 V. ainoyiKi, V. sirida, V. coninla ; and as the male parent 

 the improved forms of V. tricolor. Every shade of these 

 distinct colours — yellow, white, blue, and purple — were 

 to be found, as well as a number of beautifully striped 

 sind spotted forms, wliich, when better known, will be 

 very ornamental boi-der or rock garden plants. All are 



